Conventional 3D display techniques include techniques such as active shutter glasses and fixed polarized glasses, which both are required to operate with glasses, and other techniques such as cylindrical lens and fixed grating which are not required to operate with glasses.
When using the fixed polarized glasses, a ¼ wave film is disposed at an outer side of a light-output surface of a display for transforming a linearly polarized light into a circularly polarized light. Subsequently, the light is passed through a phase retarder with fixed patterns having a phase difference of ½ wave (180 degrees), such that there is a phase retardation between the light signals which reach an observer's right eye and left eye for forming a left-handed circularly polarized light and a right-handed circularly polarized light, respectively. When the observer wears the fixed polarized glasses, the left-handed circularly polarized light and the right-handed circularly polarized light reach the left eye and the right eye, respectively, thereby forming a 3D image. The greatest disadvantage of the fixed polarized glasses is that the left eye information is required to be simultaneously shown in a frame as with the right eye information, and thus the image information being displayed on the display is reduced. At the same time, the viewing angle of the technique of the polarized glasses is limited at one direction. In addition, in the manufacturing process, the patterned retarder is required to be precisely positioned with the display, thus complicates the manufacturing process thereof. Therefore, the complicated manufacturing process deteriorates the process yield and increases manufacturing cost thereof.